Letetresgene Autoleucel Engineered T Cells Alone and in Combination With Pembrolizumab in NY-ESO-1 Positive Multiple Myeloma

Phase 1

Terminated

Conditions: Neoplasms

Interventions: Drug: Letetresgene autoleucel with pembrolizumab
Drug: Letetresgene autoleucel
Drug: Fludarabine
Drug: Cyclophosphamide
Drug: Pembrolizumab

Registration Number: NCT03168438

Lead Sponsor: GlaxoSmithKline

Brief Summary: This trial will evaluate safety, tolerability, and efficacy of letetresgene autoleucel (GSK3377794) with or without pembrolizumab in participants with relapsed and refractory multiple myeloma.

Detailed Description: Not available

Recruitment & Eligibility

Status: TERMINATED

Sex: All

Target Recruitment: 6

Inclusion Criteria

Age >=18 years of age or older on the date of signing informed consent.
Histologically confirmed diagnosis of secretory multiple myeloma with myeloma markers at levels defined in the protocol.
Documented diagnosis of relapsed and refractory multiple myeloma (RRMM) (at least 3 prior regimens and responsive to at least 1, and refractory to most recent prior therapies, which must have included one or more than one drug from each of the following drug classes: an immunomodulatory imide drug (IMiD), proteasome inhibitor, alkylator (unless the participant is ineligible or contraindicated to receive an alkylator), CD 38 monoclonal antibody, and glucocorticoid as separate lines or a combined line of therapy.- Left ventricular ejection fraction (LVEF) >= 50%. Lower LVEF (>= 40%) permissible if formal cardiologic evaluation reveals no evidence for clinically significant functional impairment.
Meets protocol criteria for patients who have previously received checkpoint inhibitors or other immuno-oncology agents.
ECOG Performance Status 0 or 1.
Participant is HLA-A*02:01, HLA-A*02:05, and/or HLA-A*02:06 positive as determined by a designated central laboratory.
Participant has confirmed sufficient expression of NY-ESO-1 and/or LAGE-1a as determined by a designated central laboratory.
In the Investigator's opinion, the participant is fit for cell collection.
Participant has adequate organ function and cell counts as described in the protocol.
Participants previously treated with BCMA therapy (BCMA chimeric antigen receptor (CAR)-T, antibody-drug conjugate (ADC), or other type of BCMA-targeted therapy) must have progressed from this therapy prior to attending the Baseline visit prior to beginning lymphodepletion.
Contraception use by male and female participant meets protocol requirements.

Exclusion Criteria

Has only plasmacytomas, plasma cell leukemia, monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), non-secretory myeloma or primarily amyloidosis.
Previously received anti- programmed death (PD)-1, anti-PD-ligand (L)1, or anti-PD-L2 inhibitor.
Previously participated in Merck pivotal trial NCT02576977: Study of Pomalidomide and Low Dose Dexamethasone With or Without Pembrolizumab in Refractory or RRMM.
Had a prior allogeneic stem cell transplant.
Has ongoing toxicity from previous anticancer therapy.
Had a major surgery within 4 weeks prior to enrollment.
Has history of allergic reactions to fludarabine, cyclophosphamide or agents similar to fludarabine, cyclophosphamide or other agents used in the study.
Known history of myelodysplasia.
Current active liver or biliary disease.
Known history of chronic active hepatitis or liver cirrhosis.
Participant has an active viral infection.
History of severe immune disease, including non-infectious pneumonitis, requiring steroids or other immunosuppressive treatments.
Active immune-mediated diseases.
Prior or active demyelinating disease.
Evidence or history of significant cardiac disease.
Evidence or history of other significant, hepatic, renal, ophthalmologic, psychiatric, or gastrointestinal disease.
Participants with concomitant second malignancies (except adequately treated non-melanomatous skin cancers, carcinoma in situ of the breast, treated superficial bladder cancer or prostate cancer, or in situ cervical cancers ) not in complete remission.
Known active central nervous system (CNS) metastases and/or carcinomatous meningitis. Participants with previously treated brain metastases may be eligible.
Active bacterial or systemic viral or fungal infections.
Pregnant or breastfeeding.
Cannot meet washout periods for prior radiotherapy, chemotherapy or other protocol-specified therapies.
More than 2 years have passed since the participant's last leukapheresis collection.

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Arm 2: Letetresgene autoleucel (GSK3377794) with pembrolizumab	Cyclophosphamide	Eligible participants will be leukapheresed to manufacture engineered T-cells. Participants will then receive letetresgene autoleucel (GSK3377794), as a single intravenous (IV) infusion after completing lymphodepleting chemotherapy, followed by pembrolizumab 200 mg every 3 weeks.
Arm 2: Letetresgene autoleucel (GSK3377794) with pembrolizumab	Letetresgene autoleucel with pembrolizumab	Eligible participants will be leukapheresed to manufacture engineered T-cells. Participants will then receive letetresgene autoleucel (GSK3377794), as a single intravenous (IV) infusion after completing lymphodepleting chemotherapy, followed by pembrolizumab 200 mg every 3 weeks.
Arm 2: Letetresgene autoleucel (GSK3377794) with pembrolizumab	Fludarabine	Eligible participants will be leukapheresed to manufacture engineered T-cells. Participants will then receive letetresgene autoleucel (GSK3377794), as a single intravenous (IV) infusion after completing lymphodepleting chemotherapy, followed by pembrolizumab 200 mg every 3 weeks.
Arm 2: Letetresgene autoleucel (GSK3377794) with pembrolizumab	Pembrolizumab	Eligible participants will be leukapheresed to manufacture engineered T-cells. Participants will then receive letetresgene autoleucel (GSK3377794), as a single intravenous (IV) infusion after completing lymphodepleting chemotherapy, followed by pembrolizumab 200 mg every 3 weeks.
Arm 1: Letetresgene autoleucel (GSK3377794)	Fludarabine	Eligible participants will be leukapheresed to manufacture engineered T-cells. Participants will then receive letetresgene autoleucel (GSK3377794), as a single intravenous (IV) infusion after completing lymphodepleting chemotherapy.
Arm 1: Letetresgene autoleucel (GSK3377794)	Cyclophosphamide	Eligible participants will be leukapheresed to manufacture engineered T-cells. Participants will then receive letetresgene autoleucel (GSK3377794), as a single intravenous (IV) infusion after completing lymphodepleting chemotherapy.
Arm 1: Letetresgene autoleucel (GSK3377794)	Letetresgene autoleucel	Eligible participants will be leukapheresed to manufacture engineered T-cells. Participants will then receive letetresgene autoleucel (GSK3377794), as a single intravenous (IV) infusion after completing lymphodepleting chemotherapy.

Primary Outcome Measures

Name	Time	Method
Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)	Up to 108 weeks	An AE is any untoward medical occurrence in a participant or clinical investigation participant who received a study treatment and the event need not necessarily have a causal relationship with study treatment. An SAE is any AE that results in death; is life-threatening; requires hospitalization or prolongation of existing hospitalization; results in a persistent or significant disability; is a congenital anomaly/birth defect; is clinically significant or requires intervention to prevent one of the outcomes listed before.
Number of Participants With Treatment Limiting Toxicities-GSK3377794+Pembrolizumab Arm Only	Up to 3 weeks	The following toxicities were considered to be treatment limiting toxicities: any \>=Grade 4 AE; Grade 3 non-infectious pneumonitis and any other Grade 3 AE (excluding pneumonitis), that did not improve to Grade 2 within 7 days after onset despite medical management and supportive care. Exceptions included the following: Grade 3 or 4 leukopenia, lymphopenia, neutropenia, or febrile neutropenia; Grade 3 or 4 thrombocytopenia not associated with significant bleeding; Grade 3 anemia; Grade 4 cytokine release syndrome (CRS) or toxicities related to CRS that resolved to Grade \<=2 within 7 days; other Grade 3 laboratory abnormality determined to be not clinically significant by the Investigator; Grade 3 or 4 fever and chills; Grade 3 or 4 hypoalbuminemia or abnormal electrolytes that responded to supplementation/correction; AE related to the cancer or its progression.
Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to Baseline	Up to 108 weeks	Blood samples were collected for the assessment of following clinical chemistry parameters: glucose, albumin, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, creatinine, potassium, magnesium, phosphate, sodium and calcium. Laboratory parameters were graded according to National Cancer Institute-Common Toxicity Criteria for Adverse Events (NCI-CTCAE) version 4.03 where, Grade1: mild; Grade 2: moderate; Grade 3: severe or medically significant; Grade 4: life-threatening consequences. An increase in grade is defined as an increase in CTCAE grade relative to Baseline grade. Data for any grade increase at worst case post Baseline is presented.
Number of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to Baseline	Up to 108 weeks	Blood samples were collected for the assessment of following hematology parameters: hemoglobin, lymphocytes, neutrophils, platelets and leukocytes. Laboratory parameters were graded according to NCI-CTCAE version 4.03 where, Grade1: mild; Grade 2: moderate; Grade 3: severe or medically significant; Grade 4: life-threatening consequences. An increase in grade is defined as an increase in CTCAE grade relative to Baseline grade. Data for any grade increase at worst case post Baseline is presented.
Number of Participants With Worst-case Results for Coagulation Parameters Relative to Normal Range Post-Baseline Relative to Baseline	Up to 108 weeks	Blood samples were collected for the assessment of following coagulation parameters: prothrombin time and partial thromboplastin time (PTT). A laboratory value that is outside the normal range is considered either high abnormal (value above the upper limit of the normal range) or low abnormal (value below the lower limit of the normal range). Participants were counted twice if the participant had values in 'Decreased to low' and 'Increased to high' during the post-Baseline period. Data for worst case post Baseline is presented.
Number of Participants With Worst-case Post Baseline Abnormal Electrocardiogram (ECG) Findings	Up to 108 weeks	ECG was recorded using an ECG machine that automatically calculated the heart rate and measured PR, RR, QRS and QT duration corrected for heart rate by Fridericia's formula (QTcF) intervals. Data for number of participants with abnormal clinically significant ECG findings for worst case post-Baseline has been presented. Clinically significant abnormal laboratory findings are those which are not associated with the underlying disease, unless judged by the investigator to be more severe than expected for the participant's condition.

Secondary Outcome Measures

Name	Time	Method
Overall Response Rate	Up to 108 weeks	Overall response rate is defined as the percentage of participants with a best overall response (BOR) of confirmed stringent complete response (sCR), complete response (CR), very good partial response (VGPR), or partial response (PR) per International Myeloma Working Group (IMWG) Response Criteria (2016); where, PR: \>=50% reduction of serum M-Protein and reduction in 24-hour urinary M-protein by \>=90% or to \<200 milligrams (mg) per 24 hours; VGPR: Serum and urine M-protein detectable by immunofixation but not on electrophoresis or 90% or greater reduction in serum M-protein plus urine M-protein level \<100 mg per 24 hours; CR: Negative immunofixation on the serum and urine and disappearance of any soft tissue plasmacytomas and \<= 5% plasma cells in bone marrow; or sCR: CR as defined by normal free light chain (FLC) ratio and absence of clonal cells by immunohistochemistry. Confidence intervals were calculated using the exact (Clopper-Pearson) method.
Time to Response	Up to 108 weeks	Time to response is defined as the time interval (in months) from T-cell infusion to initial date of documented confirmed response (PR or better) in the subset of participants who showed a confirmed BOR of PR or better by Investigator assessment per IMWG (2016).
Duration of Response	Up to 108 weeks	Duration of response is defined as the interval between the initial date of the confirmed response (sCR, CR, VGPR, or PR) and the initial assesment date of confirmed progressive disease or death among participants with a confirmed response per IMWG (2016).
Progression-free Survival	Up to 108 weeks	Progression Free Survival is defined as the interval between the date of T-cell infusion and the initial assessment date of confirmed progressive disease as assessed by the investigator per IMWG (2016) or date of death. Progressive disease is defined as an increase of 25% from lowest confirmed response value in 1 or more of the following criteria: Serum M-protein with absolute increase of \>=0.5 grams per deciliter (g/dL); Serum M-protein increase \>=1 g/dL if the lowest M-component was \>=5 g/dL; Urinary M-protein (absolute increase must be \>=200 mg per 24 hours).
Maximum Persistence (Cmax) of GSK3377794	Up to 108 weeks	Blood samples were collected to measure persistence of infused GSK3377794 using polymerase chain reaction of a vector specific sequence in deoxyribonucleic acid (DNA) extracted from peripheral blood mononuclear cell (PBMC).
Time to Maximum Persistence	Up to 108 weeks	Blood samples were collected to measure persistence of infused GSK3377794 using polymerase chain reaction of a vector specific sequence in DNA extracted from PBMC.
Area Under the Plasma Concentration-time Curve From Zero to Day 28 (AUC[0-28])	Up to Day 28	Blood samples were collected to measure persistence of infused GSK3377794 using polymerase chain reaction of a vector specific sequence in DNA extracted from PBMC.